The DuraHeart LVAS is designed to provide long-term support for patients who cannot undergo heart transplantation because of donor availability or other factors. The DuraHeart LVAS received the CE mark in February 2007 and is commercially available in Europe. In the United States, the DuraHeart may only be used for investigational purposes. In July 2008, an FDA-approved clinical trial was initiated to study the device for use as a bridge to heart transplantation.

The Pump

The DuraHeart is a small, implantable centrifugal blood pump. The system has 3 main parts: the pump, an inflow conduit, and an outflow conduit. The pump connects to its external components with a driveline that exits the skin. The DuraHeart pump weighs about 19 ounces (about 540 grams) and is 2.9 inches (7.3 cm) in diameter and 1.8 inches (45 mm) thick.

The internal pump system is made of titanium and stainless steel. Within the pump is an impeller that looks like a paddlewheel. Magnetic levitation technology uses electromagnetic coils and position sensors to keep the impeller precisely positioned within the pump. A tiny gap (250 microns) between the impeller and the pump's walls ensures even blood flow and reduces the risk of damage to blood cells.

The pump is placed in pocket created in the upper abdomen. The pump works by drawing blood into the impeller and moving the blood toward the outside walls and through the outflow conduit. The pump speed can vary and is capable of providing blood flow of up to 8 liters per minute. The pump is sensitive to heart rate and activity levels, so the pump speed will vary in response to different levels of patient or cardiac activity. A cable connects the pump to a rechargeable battery worn outside the body.

External Equipment

The main external components are an externally worn controller and 2 battery packs. Patients can move about for up to 5 hours by using 2 fully charged batteries, and patients can extend this time by carrying extra batteries.